UPDATE: Crews Have Contained 70 Percent Of Smith Mountain Fire

Firefighters now have contained 70 percent of the Smith Mountain fire about 40 miles southeast of Casper, according to a news release form the U.S. Bureau of Land Management on Thursday.

The wildfire is estimated to be 100 percent contained by Sunday, said Frank Keeler, the BLM's High Desert District fire management officer.

"We are still focused on containing the wildfire and providing for the safety of those on the ground," Keeler said.

The wildfire had grown to 800 acres from 700 acres on Sunday. No structures have been lost.

The BLM still wants to know how an intentional prescribed burn grew to a 700-acre wildfire on Sunday, BLM spokesman Tony Brown said on Tuesday. "The reason for this being out of control is still under investigation because we still don't know what happened."

The controlled burn intended to improve wildlife habitat, increase livestock forage and distribution, enhance range land and vegetation health, reduce hazardous fuels, and open areas to grasses, wildflowers, and new and more palatable shrubs and aspen.

The BLM conducts these burns in the fall and winter, and monitors weather conditions, Brown said.

But somehow it escaped its confined area and expanded into hilly terrain with a variety of shrubs, aspens and conifers, he said.

The BLM has received assistance from Albany County, the Wyoming State Forestry Division and the Medicine Bow National Forest, he said. Dispatched resources include: four engines, two helicopters, one Type-I hot shot crew and two TYPE-II IA hand crews.

The public is urged to use caution and avoid the area because fire behavior can change and fire spread is unpredictable if high winds develop.

The BLM urges people to report wildfires immediately to the Rawlins Dispatch Center at 1-800-295-9953, or by calling 911.